The idle mode is a working mode of an MS in a mobile broadband Radio Access System (RAS) defined by the IEEE 802.16e standard. In the idle mode, an MS moves in a large area, and receives the downlink broadcast service information at a specific interval. Broadcast messages are used to notify the MS whether any downlink service needs to be transmitted. While roaming in an area, an MS does not need to get registered on the Base Station (BS) of the roaming cell. Meanwhile, while roaming in different cells, the MS does not need to perform usual operation processes such as handover, which is conducive to saving MS power and air interface resources.
Multiple BSs make up a group, a Paging Group (PG). A PG is intended to constitute a continuous area, inside which the MS does not need to send uplink services but can use downlink paging channels to judge whether any downlink service is sent to the MS.
In the normal operation process on a serving BS, the MS may request to enter the idle mode by sending a message. Likewise, a serving BS can require an MS to enter the idle mode by sending a message. No matter whether the MS requests to enter the idle mode through a message or the serving BS requires the MS to enter the idle mode through a message, the MS needs to finish deregistration and enter the idle mode within the specified time segment.
The Worldwide Interoperability for Microwave Access (WiMAX) standard under development now defines a paging reference model in the idle mode. In the WiMax NWG standard draft, the function entities closely related to the idle mode and paging include:
a Paging Controller (PC), as a network entity for controlling activity of an MS in the idle mode, is designed to manage the activity and paging of the MS in the idle mode in a network. A PC may be located in an Access Service Network Gateway (ASN GW) which is a physical Network Element (NE) in a WiMAX network, or located in another stand-alone physical NE. For each MS in the idle mode, only one PC works to manage its activities, and is called anchor PC; and one or more PCs work to relay the messages from the MS to the anchor PC, and are called relay PC;
a Paging Agent (PA) is located in an ASN, and is designed to handle interaction for executing paging-related functions in the PC and the BS; and
a Location Register (LR) is a distributed database, which stores information about the MS in the idle mode. A PC needs to send paging messages according to the PG currently containing the MS. Therefore, an LR is required for saving the state information, paging information and service stream information of the MS. Generally, each LR corresponds to one PC, and two logic entities work in the same logic entity.
As required, a Network Access Point (NAP) divides a network into several Paging Groups (PGs). One PG consists of one or more PAs (BSs), and is managed by the network operator. One PG must reside in a NAP. A BS and the related PAs may be entities in multiple PGs.
Regardless of other physical NEs and logic entities in the WiMAX network, the following description is made with respect to the WiMAX paging reference architecture shown in FIG. 1 (the technical solution under the present invention includes but is not limited to the application in a WiMAX system).
According to the paging reference model shown in FIG. 1, when an MS requests to enter the idle mode on BS1 (a serving BS), or BS1 instructs the MS to enter the idle mode, message interaction is performed between the MS and the BS1, between the BS1 and the back-end NE “ASN GW” to notify the PC that the MS enters the idle mode (this is implemented in the ASN GW1). The state information, paging information and service stream information of the MS are saved in the corresponding LR. After the MS enters the idle mode, the corresponding R4 and R6 interfaces need to be released, but the R3 interface between the Home Agent (HA) and the Foreign Agent (FA) must be reserved.
In the prior art, after a service occurs on the MS, the process of paging an MS at the network side is: The FA receives a downlink packet sent by the HA to the MSS, detects that the Mobile Subscriber Station (MSS) is in the idle mode, and hence sends an MSS Info Req message to the anchor PC, instructing the PC to page the MSS. After obtaining the information about the MSS, the anchor PC/LR replies with an MSS Info Rsp message. The anchor PC sends a Paging Announce message to the PA under its direct management; and sends a Paging Announce message to the relay PC that manages the PA if the PA is not directly managed by the anchor PC but is located in the corresponding PG After receiving the Paging Announce message, the PC forwards the message to the corresponding PA. After receiving the Paging Announce message, the PA initiates paging to the MS from an air interface.
In the prior art, however, an attempt of paging results in drastic waste of air interface resources, and increases complexity for allocation of the air interface resources. Moreover, the prior art does not describe how to instruct other BS to stop paging after the MS is paged successfully.